Optical device

ABSTRACT

An optical device including a first substrate, a light source, a second substrate, an image capturing device, a microstructure layer, and an infrared pass layer is provided. The light source is disposed on the first substrate. The second substrate is disposed above the first substrate. The second substrate includes a first surface and a second surface opposite to the first surface. The image capturing device is disposed on the first substrate to receive a light beam, which is originated from scattered light beams scattered by an object touching the first surface of the second substrate. The microstructure layer is disposed on the first surface of the second substrate. The microstructure layer is adapted to increase a light beam, which is scattered by the object and transmitted to the image capturing device. The infrared pass layer is adapted to pass the infrared light.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisionalapplication Ser. No. 62/241,156, filed on Oct. 14, 2015. The entirety ofthe above-mentioned patent application is hereby incorporated byreference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to an optical device, in particular, toan optical device for fingerprint collection.

2. Description of Related Art

Optical devices such as optical fingerprint collection devices arewidely used for fingerprint collection and identification. Thecollection of fingerprints through optical devices is based on opticalimaging the finger surface through optical sensors. Most conventionaloptical devices for fingerprint collection, such as a reflection typefingerprint reader, use a prism which is directly contacted by a fingerof the user, and a light source and an image capture unit is installedat different side of the prism. Through total internal reflection andfrustrated total internal reflection (FTIR), the ridge-valley patternsof a fingerprint may produce a high contrast fingerprint image. On theother hand, some optical devices for fingerprint collection use atransmission type fingerprint reader to collect the fingerprint. Lightsignals are transmitted into the finger and then scattered back to theimage capture unit. In certain related arts, the light signals may gothrough the whole finger.

For an electronic device having fingerprint collection function, how tomanufacture an embeddable optical fingerprint collection device that haslow cost, strong mechanical strength, and satisfactory sensing qualityis one of the most important topics in the pertinent field.

SUMMARY OF THE INVENTION

Accordingly, the invention is directed to an optical device forfingerprint collection, capable of being embedded into an electronicdevice.

An exemplary embodiment of the invention provides an optical deviceincluding a first substrate, a light source, a second substrate, animage capturing device, a microstructure layer, and an infrared passlayer. The light source is disposed on the first substrate to output afirst light beam, which is an infrared light. The second substrate isdisposed above the first substrate. The second substrate includes afirst surface and a second surface opposite to the first surface andrelatively close to the first substrate. A scattered light beam which isgenerated by the first light beam entering an object touching the firstsurface of the second substrate and scattered in the object is a secondlight beam. The image capturing device is disposed on the firstsubstrate to receive a third light beam. The third light beam is thesecond light beam normally incident to the second surface andtransmitted to the image capturing device. The microstructure layer isdisposed on the first surface of the second substrate. Themicrostructure layer is adapted to increase a third light beam. Theinfrared pass layer is adapted to pass the infrared light.

In an exemplary embodiment of the invention, the infrared pass layer isdisposed on one of the microstructure layer, the first surface of thesecond substrate, the second surface of the second substrate, and theimage capturing device.

In an exemplary embodiment of the invention, the optical device furtherincludes at least one anti-reflective layer. The at least oneanti-reflective layer is disposed on at least one of the first surfaceand the second surface of the second substrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a first light shielding structure. The first light shieldingstructure is disposed on the first substrate and connected to the secondsubstrate. The first light shielding structure locates between the lightsource and the image capturing device.

In an exemplary embodiment of the invention, the optical device furtherincludes a second light shielding structure. The second light shieldingstructure is disposed on the first substrate and connected to the secondsubstrate. The first light shielding structure and the second lightshielding structure enclose the light source.

In an exemplary embodiment of the invention, the optical device furtherincludes a third light shielding structure. The third light shieldingstructure is disposed on the first substrate, and locates between thelight source and the image capturing device. The third light shieldingstructure extends toward the second substrate, and one end portion ofthe third light shielding structure is embedded into the secondsubstrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a fourth light shielding structure. The fourth light shieldingstructure is disposed on the first substrate, and locates between thelight source and the image capturing device. The fourth light shieldingstructure extends toward the second substrate, and one end portion ofthe light shielding structure has a support shape to support the secondsubstrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a light guiding structure. The light guiding structure isdisposed on the second surface of the second substrate and above thelight source. The light guiding structure is adapted to guide the firstlight beam from the light source to the second substrate.

In an exemplary embodiment of the invention, the second substrate ismade of a cover layer on a display panel of an electronic device.

Another exemplary embodiment of the invention provides an optical deviceincluding a first substrate, a light source, a second substrate, animage capturing device, and a light absorbing layer. The light source isdisposed on the first substrate to output a first light beam, which isan infrared light. The second substrate is disposed above the firstsubstrate. The second substrate includes a first surface and a secondsurface opposite to the first surface and relatively close to the firstsubstrate. A scattered light beam which is generated by the first lightbeam entering an object touching the first surface of the secondsubstrate and scattered in the object is a second light beam. The imagecapturing device is disposed on the first substrate to receive a thirdlight beam. The third light beam is the second light beam normallyincident to the second surface and transmitted to the image capturingdevice. The light absorbing layer is disposed on one of the firstsurface and the second surface of the second substrate. A normalprojection of the light absorbing layer on the first substrate locatesbetween the light source and the image capturing unit.

In an exemplary embodiment of the invention, the optical device furtherincludes an infrared pass layer. The infrared pass layer is disposed onone of the first surface of the second substrate, the second surface ofthe second substrate and the image capturing device, and adapted to passthe infrared light. The infrared pass layer is adapted to pass theinfrared light.

In an exemplary embodiment of the invention, the optical device furtherincludes a microstructure layer. The microstructure layer is disposed onthe first surface of the second substrate. The microstructure layer isadapted to increase the third light beam.

In an exemplary embodiment of the invention, the optical device furtherincludes an infrared pass layer. The infrared pass layer is disposed onone of the microstructure layer, the first surface of the secondsubstrate, the second surface of the second substrate, and the imagecapturing device. The infrared pass layer is adapted to pass theinfrared light.

In an exemplary embodiment of the invention, the light absorbing layeris adapted to absorb a fourth light beam transmitted in the secondsubstrate along a horizontal direction.

In an exemplary embodiment of the invention, the optical device furtherincludes at least one anti-reflective layer. The at least oneanti-reflective layer is disposed on at least one of the first surfaceand the second surface of the second substrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a first light shielding structure. The first light shieldingstructure is disposed on the first substrate and connected to the secondsubstrate. The first light shielding structure locates between the lightsource and the image capturing device.

In an exemplary embodiment of the invention, the optical device furtherincludes a second light shielding structure. The second light shieldingstructure is disposed on the first substrate and connected to the secondsubstrate. The first light shielding structure and the second lightshielding structure enclose the light source.

In an exemplary embodiment of the invention, the optical device furtherincludes a third light shielding structure. The third light shieldingstructure is disposed on the first substrate, and locates between thelight source and the image capturing device. The light shieldingstructure extends toward the second substrate, and one end portion ofthe light shielding structure is embedded into the second substrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a fourth light shielding structure. The fourth light shieldingstructure is disposed on the first substrate, and locates between thelight source and the image capturing device. The fourth light shieldingstructure extends toward the second substrate, and one end portion ofthe fourth light shielding structure has a support shape to support thesecond substrate.

In an exemplary embodiment of the invention, the optical device furtherincludes a light guiding structure. The light guiding structure isdisposed on the second surface of the second substrate and above thelight source. The light guiding structure is adapted to guide the firstlight beam from the light source to the second substrate.

In an exemplary embodiment of the invention, the second substrate ismade of a cover layer on a display panel of an electronic device.

According to the above descriptions, in the exemplary embodiments of theinvention, the optical device includes a microstructure layer and aninfrared pass layer. Alternatively, the optical device includes a lightabsorbing layer. Accordingly, the optical device for fingerprintcollection embedded into the electronic device provides a good sensingquality.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 illustrates an exploded view of an optical device according to anembodiment of the invention.

FIG. 2 illustrates a sectional view of the optical device depicted inFIG. 1 along line A-A′.

FIG. 3 illustrates a schematic diagram of the second substrate depictedin FIG. 1 with optical films according to an embodiment of theinvention.

FIG. 4 illustrates a schematic diagram of an electronic device accordingto an embodiment of the invention.

FIG. 5 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 6 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 7 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 8 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 9 illustrates an exploded view of an optical device according toanother embodiment of the invention.

FIG. 10 illustrates a sectional view of the optical device depicted inFIG. 9 along line B-B′.

FIG. 11 illustrates a bottom view of the second substrate with the lightabsorbing layer depicted in FIG. 10.

FIG. 12 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 13 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 14 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 15 illustrates a sectional view of an optical device according toanother embodiment of the invention.

FIG. 16 illustrates a sectional view of an optical device according toanother embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

The term “coupling/coupled” used in this specification (includingclaims) of the disclosure may refer to any direct or indirect connectionmeans. For example, “a first device is coupled to a second device”should be interpreted as “the first device is directly connected to thesecond device” or “the first device is indirectly connected to thesecond device through other devices or connection means.” In addition,the term “signal” can refer to a current, a voltage, a charge, atemperature, data, electromagnetic wave or any one or multiple signals.

FIG. 1 illustrates an exploded view of an optical device according to anembodiment of the invention. FIG. 2 illustrates a sectional view of theoptical device depicted in FIG. 1 along line A-A′. Referring to FIG. 1and FIG. 2, an optical device 100A of the present embodiment includes afirst substrate 110, a light source 130, a second substrate 120, animage capturing device 140, a light shielding structure 151 (the firstlight shielding structure), a supporting member 160, and a lens module170.

In the present embodiment, the light source 130 is disposed on the firstsubstrate 110 to output a first light beam I1. In an embodiment, thefirst light beam I1 is an infrared light. The first light beam I1 hasintensity enough to be transmitted through the second substrate 120 andinto an object 200. The light source 130 may include one or more lightemitting devices surrounding the image capturing device 140 asillustrated in FIG. 1. The arrangement of the light source 130 on thefirst substrate 110 is not intended to limit the invention. The secondsubstrate 120 is disposed above the first substrate 110. The secondsubstrate 120 includes a first surface S1 and a second surface S2. Thesecond surface S2 is opposite to the first surface S1 and relativelyclose to the first substrate 110. In the present embodiment, the firstsubstrate 110 is a printed circuit board, and the second substrate 120may be made of glass, ceramics or acrylic, and the invention is notlimited thereto. In an embodiment, a visible light source with highintensity, e.g. a red light source of high intensity, may be adopted forthe light source 130.

In the present embodiment, the first light beam I1 is originallytransmitted from the light source 130, and transmitted through thesecond substrate 120 into the object 200 touching the first surface S1of the second substrate 120. The first light beam I1 is scattered inobject 200 to generate second light beams I2 in various directions. Apart of the second light beams I2 that are normally incident to thesecond surface S2 are transmitted through the second substrate 120 to beas third light beams I3 transmitted toward the image capturing device140, and enters the image capturing device 140. In the presentembodiment, the image capturing device 140 is disposed on the firstsubstrate 110 to receive the third light beams I3. It is noted that thesecond light beam I2 shown in the drawings is an example and thedirection of the depicted second light beam I2 does not mean alimitation but indicate that the second light beam I2 is a scatteredlight beam (in any possible direction), scattered in the object 200.

In the present embodiment, the object 200 may be a finger of a user, andthus the optical device 100A is configured for fingerprint collection.In the present embodiment, the image capturing device 140 includes, forexample, a charge coupled device image sensor (CCD image sensor) or acomplementary metal oxide semiconductor (CMOS) image sensor or the like,which are not particularly limited by the invention. In the applicationsof the optical device 100A or the other optical device described in thefollowing, the object 200 is not limited to finger. The object 200 canbe, but not limited to, a biological texture such as palm print, or abiological signal such as pulse signal.

In the present embodiment, the light shielding structure 151 is disposedon the first substrate 110 and connected to the second substrate 120.The light shielding structure 151 is located between the light source130 and the image capturing device 140. In the present embodiment, thelight shielding structure 151 may serve as a light shielding mechanismto avoid environment lights entering the image capturing device 140;more precisely, the light shielding structure 151 may be used foravoiding other light beams (generated in a different way from the secondlight beam I2) entering the image capturing device 140. In the presentembodiment, the light shielding structure 151 may also serve as asupporting member to support the second substrate 120. In the presentembodiment, the light shielding structure 151 may also serve as aholder, and the lens module 170 is disposed on the light shieldingstructure 151. The lens module 170 is configured to focus the thirdlight beams I3 to be captured by the image capturing device 140. Forclarity, the lens module 170 is not illustrated in FIG. 2. In addition,the supporting member 160 of the present embodiment is disposed on thefirst substrate 110 and connected to the second substrate 120, so as tosupport the second substrate 120.

In the present embodiment, the lens module 170 may include one or morelenses disposed on the transmission path of the second light beam I2between the second substrate 120 and the image capturing device 140. Inan embodiment, the lens module 170 may at least include a non-plane lenswith a refractive power, for example, a biconcave lens, a biconvex lens,a concave-convex (negative meniscus) lens, a convex-concave (positivemeniscus) lens, a plano-convex lens, a plano-concave lens, etc. In anembodiment, the lens module 170 may also include a planar lens. Theimplementation and type of the lens module 170 are not limited in theinvention.

FIG. 3 illustrates a schematic diagram of the second substrate depictedin FIG. 1 with optical films according to an embodiment of theinvention. Referring to FIG. 1 to FIG. 3, the optical device 100A of thepresent embodiment further includes a microstructure layer 122, aninfrared pass layer 124, and an anti-reflective layer 126.

In the present embodiment, the microstructure layer 122 is disposed onthe first surface S1 of the second substrate 120. The microstructurelayer 122 is adapted to increase the third light beams I3, which areapart of the second light beams I2 that are normally incident to thesecond surface S2 and transmitted through the second substrate 120 tothe image capturing device 140. In the present embodiment, the thirdlight beam I3 may substantially normally enter the image capturingdevice 140 to increase the quality of the image of the object 200, e.g.,fingerprint, captured by the image capturing device 140. In the presentembodiment, the microstructure layer 122 may include a plurality of ballparticles with diameters ranging from 10 to 100 micrometers to serve asmicrostructures for scattering light beams. However, the shape, thematerial, and the size of the ball particles are not intended to limitthe invention. In an embodiment, the microstructure layer 122 may bemade by applying a surface processing on a surface of an originalmaterial of the second substrate 120 such that the material after thesurface processing has a rough, not smooth surface, which can beregarded as so-called microstructure layer in combination with thesecond substrate 120. The infrared pass layer 124 is adapted to pass theinfrared light. More specifically, the infrared pass layer 124 isadapted to pass only the infrared light and block (or filter) othervisible/invisible light which has a wavelength out of the range ofwavelength of infrared light. In the present embodiment, the infraredpass layer 124 is disposed on the microstructure layer 122.Alternatively, the infrared pass layer 124 may be disposed on the firstsurface S1 of the second substrate 120 and located between themicrostructure layer 122 and the second substrate 120 in anotherembodiment, or the infrared pass layer 124 may be disposed on the secondsurface S2 of the second substrate 120 in still another embodiment, orthe infrared pass layer 124 may be disposed on the image capturingdevice 140 in still another embodiment. The location of the infraredpass layer 124 is not intended to limit the invention. In anotherexemplary embodiment that the visible light (such as red light) sourcewith high intensity is adopted for the light source 130, the infraredpass layer 124 may be replaced by a red visible light pass layer, whichpasses the red light. In another embodiment, the second substrate 120may be made for implementing the function of the infrared pass layer124, and in such a case the infrared pass layer 124 of FIG. 3 is nolonger required. For example, a specific dyeing material which realizespassing only the infrared lights may be added into the material of thesecond substrate 120 (such as acrylic or glass) during manufacturing thesecond substrate 120.

In the present embodiment, the anti-reflective layer 126 is disposed onthe second surface S2 of the second substrate 120 to reduce light beamsthat are reflected from the second surface S2 and directly enter theimage capturing device 140 without being transmitted into the object200, when incident light beams emitted by the light source 130 travelstoward the second surface S2 of the second substrate 120. In the presentembodiment, the anti-reflective layer 126 may be disposed on the entiresecond surface S2, or disposed on only a part of the second surface S2right above the light source 130. In another embodiment, the opticaldevice 100A may include another anti-reflective layer, different fromthe anti-reflective layer 126 of FIG. 3, disposed on the first surfaceS1 of the second substrate 120 to reduce reflected light beams at thefirst surface S1 when scattered light beams in the object 200 are beingas incident light beams to the first surface S1, so as to increase lightbeams that are originated from scattered light beams in the object 200and transmitted through the second substrate 120 to the image capturingdevice 140. In another embodiment, the optical device 100A may includean anti-reflective layer disposed on the second surface S2 such as theanti-reflective layer 126 of FIG. 3 and also another anti-reflectivelayer disposed on the second surface S1 such as the aforementioned. Inan embodiment, the anti-reflective layer 126 is optional since thereflection of light beams by the first surface S1 and the second surfaceS2 may be reduced by selecting adaptive material for the secondsubstrate 120.

FIG. 4 illustrates a schematic diagram of an electronic device accordingto an embodiment of the invention. Referring to FIG. 1 and FIG. 4, theoptical device 100A depicted in FIG. 1 may be implemented in theelectronic device 300. For example, the second substrate 120 may be madeof a cover layer on a display panel 310 of the electronic device 300 forprotecting the display panel 310 and contacting the object 200. In thepresent embodiment, the optical device 100A may be disposed on anon-display area of the display panel 310.

In the present embodiment, the display panel 310 may be a liquid crystaldisplay (LCD) panel, an organic light emitting display (OLED) panel, afield emission display (FED) panel, an electro-phoretic display (EPD)panel or a light emitting diode display panel and the like, which arenot limited in the invention. In the present embodiment, the electronicdevice 300 may be a portable electronic device having fingerprintcollection function, such as a cell phone, a tablet, a notebook, awearable electronic device having fingerprint collection function, suchas a smart watch, and the like, which is not limited in the invention.In an embodiment, the optical device 100A may be applied to a smartlock.

FIG. 5 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 2 and FIG. 5, theoptical device 100B of the present embodiment is similar to the opticaldevice 100A depicted in FIG. 2, and a main difference therebetween, forexample, lies in that the optical device 100B further includes anotherlight shielding structure 152 (the second light shielding structure).

In the present embodiment, the light shielding structure 152 is disposedon the first substrate 110 and connected to the second substrate 120.The light shielding structures 151 and 152 enclose the light source 130.The first light beam I1 is transmitted in a space between the lightshielding structures 151 and 152. In the present embodiment, the lightshielding structure 152 may serve as a light shielding mechanism toavoid environment lights entering the image capturing device 140. In thepresent embodiment, the light shielding structure 152 may also serve asa supporting member to support the second substrate 120.

FIG. 6 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 2 and FIG. 6, theoptical device 100C of the present embodiment is similar to the opticaldevice 100A depicted in FIG. 2, and a main difference therebetween, forexample, lies in that a connection between a light shielding lightstructure 153 (the third light shielding structure) and the secondsubstrate 120.

In the present embodiment, the light shielding structure 153 is disposedon the first substrate 110 and located between the light source 130 andthe image capturing device 140. The light shielding structure 153extends toward the second substrate 120. The light shielding structure153 includes a first end portion 153 a and a second end portion 153 b.One end portion, i.e. the second end portion 153 b, of the lightshielding structure 153 is embedded into the second substrate 120.Another end portion, i.e. the first end portion 153 a, of the lightshielding structure 153 is connected to the first substrate 110. In thepresent embodiment, the second substrate 120 is divided into a portionenclosed by the light shielding structure 153 and the other portion outof the light shielding structure 153 as illustrated in FIG. 6. The lightshielding structure 153 of FIG. 6 brings a benefit that is to stop thelight travelling inside the second substrate 120 and to prevent suchlight beams from being refracted, not transmitted into the object 200,and received by the image capturing device 140. This kind of receivedlight beams originated from the light travelling inside the secondsubstrate 120 is interference and may result in an inverse dark-brightpattern compared to an expected pattern resulted from the expectedreceived light beams originated from the scattered light beams (I2) inthe object 200. FIG. 7 illustrates a sectional view of an optical deviceaccording to another embodiment of the invention. Referring to FIG. 2and FIG. 7, the optical device 100D of the present embodiment is similarto the optical device 100A depicted in FIG. 2, and a main differencetherebetween, for example, lies in that a connection between a lightshielding light structure 154 (the fourth light shielding structure) andthe second substrate 120.

In the present embodiment, the light shielding structure 154 is disposedon the first substrate 110 and located between the light source 130 andthe image capturing device 140. The light shielding structure 154extends toward the second substrate 120. One end portion 154 b of thelight shielding structure 154 near the second substrate 120 has asupport shape, e.g. L-shape, to support the second substrate 120. Thesupport shape may enhance supporting strength for the second substrate120.

FIG. 8 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 7 and FIG. 8, theoptical device 100E of the present embodiment is similar to the opticaldevice 100D depicted in FIG. 7, and a main difference therebetween, forexample, lies in that the optical device 100E further has a lightguiding structure 180.

In the present embodiment, the light guiding structure 180 is disposedon the second surface S2 of the second substrate 120 and above the lightsource 130. In an embodiment, the light guiding structure 180 may befixed on the second surface S2 of the second substrate 120 and simplycontact the light shielding structure 154. Alternatively, the lightguiding structure 180 may be adhered to the light shielding structure154 in another embodiment. In an embodiment, the light guiding structure180 may approach the light source 130 and cover the light source 130 toenhance light guide efficiency, but the invention is not limitedthereto. The light-guiding structure 180 is adapted to guide the firstlight beam I1 from the light source 130 to the second substrate 120.

The detail structures of the optical devices 100B to 100E in theexemplary embodiments depicted in FIG. 5 to FIG. 8 are sufficientlytaught, suggested, and embodied in the embodiments illustrated in FIG. 1to FIG. 4, and therefore no further description is provided herein.

FIG. 9 illustrates an exploded view of an optical device according toanother embodiment of the invention. FIG. 10 illustrates a sectionalview of the optical device depicted in FIG. 9 along line B-B′. Referringto FIG. 1, FIG. 2, FIG. 9 and FIG. 10, the optical device 400A of thepresent embodiment is similar to the optical device 100A depicted inFIG. 1 and FIG. 2, and a main difference therebetween, for example, liesin that the optical device 400A further includes a light absorbing layer490. It should be noted that there is a fourth light beam I4 transmittedinside the second substrate 120 along the horizontal direction, e.g. Xdirection and/or Y direction. The fourth light beam I4 may include thefirst light beam I1 entering the second substrate 120 and/or environmentlights entering the second substrate 120. A part of the fourth lightbeam I4 may be reflected from the first surface S1, not enter the object200, and be as the incident light beams to the surface S2 and receivedby the image capturing device 140. This kind of light beam results in aninverse dark-bright pattern of the object 120 which is regarded asinterference. For example, an expected fingerprint pattern resulted fromthe light beams I3 (which are originated from the scattered second lightbeams I2 in the object 200) shows bright ridges and dark valleys, whilean interference pattern resulted from the light beam I4 shows darkridges and bright valleys which eliminates the contrast of the expectedfingerprint pattern. In the present embodiment, the light absorbinglayer 490 is disposed on the second surface S2 of the second substrate120. The light absorbing layer 490 is adapted to absorb the fourth lightbeam I4 (as the incident light beams to the surface S2) such that thefourth light beam I4 has no (or little) energy to be received to resultin the interference pattern. Accordingly, the quality of fingerprintimage captured by the image capturing device 140 is increased.

In the present embodiment, the light absorbing layer 490 may be a blackmask painted (or coated) on the second surface S2 of the secondsubstrate 120 to absorb light beams I4. The shape of the light absorbinglayer 490 may be a circle ring, a rectangle ring, a square ring, or anyclosed shape with a hollow area. The invention is not intended to limitthe shape of the light absorbing layer 490. FIG. 11 illustrates a bottomview of the second substrate with the light absorbing layer depicted inFIG. 10. Referring to FIG. 9 to FIG. 11, in the present embodiment, thenormal projection of the light absorbing layer 490 on the firstsubstrate 110 is located between the light source 130 and the imagecapturing unit 140 as illustrated in FIG. 10. The position and shape ofthe light absorbing layer 490 is considered to prevent the first lightbeam I1 and the second light beams I2 (13) from being absorbed too muchby the light absorbing layer 490, since the first light beam I1 has tobe transmitted into the object 200 though the second substrate 120 andthe second light beams I2 (13) have to be received by the imagecapturing device 140.

FIG. 12 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 10 and FIG. 12,the optical device 400B of the present embodiment is similar to theoptical device 400A depicted in FIG. 10, and a main differencetherebetween, for example, lies in that the light absorbing layer 490 isdisposed on the first surface S1 of the second substrate 120. The lightabsorbing layer 490 painted/coated on the first surface S1 is adapted toabsorb the fourth light beam I4 (as the incident light beams to thesurface S1) such that the fourth light beam I4 has no (or little) energyto be reflected from the surface S1 and generate the interferencepattern.

FIG. 13 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 5 and FIG. 13,the optical device 400C of the present embodiment is similar to theoptical device 100B depicted in FIG. 5, and a main differencetherebetween, for example, lies in that the optical device 400C furtherincludes the light absorbing layer 490. In the present embodiment, thelight absorbing layer 490 is disposed on the second surface S2 of thesecond substrate 120, and is located between the light shieldingstructure 151 and the second substrate 120. In an embodiment, the lightabsorbing layer 490 may be disposed on the first surface S1 of thesecond substrate 120.

FIG. 14 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 6 and FIG. 14,the optical device 400D of the present embodiment is similar to theoptical device 100C depicted in FIG. 6, and a main differencetherebetween, for example, lies in that the optical device 400C furtherincludes the light absorbing layer 490. In the present embodiment, thelight absorbing layer 490 is disposed on the first surface S1 of thesecond substrate 120.

FIG. 15 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 7 and FIG. 15,the optical device 400E of the present embodiment is similar to theoptical device 100D depicted in FIG. 7, and a main differencetherebetween, for example, lies in that the optical device 400E furtherincludes the light absorbing layer 490. In the present embodiment, thelight absorbing layer 490 is disposed on the first surface S1 of thesecond substrate 120. In an embodiment, the light absorbing layer 490may be disposed on the second surface S2 of the second substrate 120.

FIG. 16 illustrates a sectional view of an optical device according toanother embodiment of the invention. Referring to FIG. 8 and FIG. 16,the optical device 400F of the present embodiment is similar to theoptical device 100E depicted in FIG. 8, and a main differencetherebetween, for example, lies in that the optical device 400F furtherincludes the light absorbing layer 490. In the present embodiment, thelight absorbing layer 490 is disposed on the first surface S1 of thesecond substrate 120. In an embodiment, the light absorbing layer 490may be disposed on the second surface S2 of the second substrate 120. Itis noted that the second substrate 120 of FIGS. 9-16 also includes aninfrared pass layer (not shown) which is similar to the infrared passlayer 124 of FIG. 3. This infrared pass layer may be disposed on thefirst surface S1 of the second substrate 120, on the second surface S2of the second substrate 120, on a microstructure layer (if included), oron the image capturing device 140.

The detail structures of the optical devices 400A to 400E in theexemplary embodiments depicted in FIG. 10 and FIG. 12 to FIG. 16. aresufficiently taught, suggested, and embodied in the embodimentsillustrated in FIG. 1 to FIG. 9, and therefore no further description isprovided herein.

In summary, in the exemplary embodiments of the invention, the opticaldevice includes a microstructure layer and an infrared pass layer.Alternatively, the optical device includes a light absorbing layer.Accordingly, the optical device for fingerprint collection embedded intothe electronic device provides a good sensing quality. In addition, thesecond substrate is made of the cover layer on the display panel of theelectronic device, the light shielding structures and the supportingmember disposed on the first substrate support the second substrate.Accordingly, the supporting strength for the second substrate isenhanced.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An optical device, comprising: a first substrate;a light source, disposed on the first substrate to output a first lightbeam which is an infrared light; a second substrate, disposed above thefirst substrate, and comprising a first surface and a second surfaceopposite to the first surface and relatively close to the firstsubstrate, wherein a scattered light beam which is generated by thefirst light beam entering an object touching the first surface of thesecond substrate and scattered in the object is a second light beam; animage capturing device, disposed on the first substrate to receive athird light beam, wherein the third light beam is the second light beamnormally incident to the second surface and transmitted to the imagecapturing device; a microstructure layer, disposed on the first surfaceof the second substrate, and adapted to increase the third light beam;and an infrared pass layer, adapted to pass the infrared light.
 2. Theoptical device according to claim 1, wherein the infrared pass layer, isdisposed on one of the microstructure layer, the first surface of thesecond substrate, the second surface of the second substrate, and theimage capturing device.
 3. The optical device according to claim 1,further comprising: at least one anti-reflective layer, disposed on atleast one of the first surface and the second surface of the secondsubstrate.
 4. The optical device according to claim 1, furthercomprising: a first light shielding structure, disposed on the firstsubstrate and connected to the second substrate, and located between thelight source and the image capturing device.
 5. The optical deviceaccording to claim 4, further comprising: a second light shieldingstructure, disposed on the first substrate and connected to the secondsubstrate, wherein the first light shielding structure and the secondlight shielding structure enclose the light source.
 6. The opticaldevice according to claim 1, further comprising: a third light shieldingstructure, disposed on the first substrate, and located between thelight source and the image capturing device, wherein the third lightshielding structure extends toward the second substrate, and one endportion of the third light shielding structure is embedded into thesecond substrate.
 7. The optical device according to claim 1, furthercomprising: a fourth light shielding structure, disposed on the firstsubstrate, and located between the light source and the image capturingdevice, wherein the fourth light shielding structure extends toward thesecond substrate, and one end portion of the fourth light shieldingstructure has a support shape to support the second substrate.
 8. Theoptical device according to claim 1, further comprising: a light guidingstructure, disposed on the second surface of the second substrate andabove the light source, and adapted to guide the first light beam fromthe light source to the second substrate.
 9. The optical deviceaccording to claim 1, wherein the second substrate is made of a coverlayer on a display panel of an electronic device.
 10. An optical device,comprising: a first substrate; a light source, disposed on the firstsubstrate to output a first light beam which is an infrared light; asecond substrate, disposed above the first substrate, and comprising afirst surface and a second surface opposite to the first surface andrelatively close to the first substrate, wherein a scattered light beamwhich is generated by the first light beam entering an object touchingthe first surface of the second substrate and scattered in the object isa second light beam; an image capturing device, disposed on the firstsubstrate to receive a third light beam, wherein the third light beam isthe second light beam normally incident to the second surface andtransmitted to the image capturing device; and a light absorbing layer,disposed on one of the first surface and the second surface of thesecond substrate, wherein a normal projection of the light absorbinglayer on the first substrate locates between the light source and theimage capturing unit.
 11. The optical device according to claim 10,further comprising: an infrared pass layer, disposed on one of the firstsurface of the second substrate, the second surface of the secondsubstrate and the image capturing device, and adapted to pass theinfrared light.
 12. The optical device according to claim 10, furthercomprising: a microstructure layer, disposed on the first surface of thesecond substrate, and adapted to increase the third light beam.
 13. Theoptical device according to claim 12, further comprising: an infraredpass layer, disposed on one of the microstructure layer, the firstsurface of the second substrate, the second surface of the secondsubstrate, and the image capturing device, wherein the infrared passlayer is adapted to pass the infrared light.
 14. The optical deviceaccording to claim 10, wherein the light absorbing layer is adapted toabsorb a fourth light beam transmitted in the second substrate along ahorizontal direction.
 15. The optical device according to claim 10,further comprising: at least one anti-reflective layer, disposed on atleast one of the first surface and the second surface of the secondsubstrate.
 16. The optical device according to claim 10, furthercomprising: a first light shielding structure, disposed on the firstsubstrate and connected to the second substrate, and located between thelight source and the image capturing device.
 17. The optical deviceaccording to claim 16, further comprising: a second light shieldingstructure, disposed on the first substrate and connected to the secondsubstrate, wherein the first light shielding structure and the secondlight shielding structure enclose the light source.
 18. The opticaldevice according to claim 10, further comprising: a third lightshielding structure, disposed on the first substrate, and locatedbetween the light source and the image capturing device, wherein thethird light shielding structure extends toward the second substrate, andone end portion of the third light shielding structure is embedded intothe second substrate.
 19. The optical device according to claim 10,further comprising: a fourth light shielding structure, disposed on thefirst substrate, and located between the light source and the imagecapturing device, wherein the fourth light shielding structure extendstoward the second substrate, and one end portion of the fourth lightshielding structure has a support shape to support the second substrate.20. The optical device according to claim 10, further comprising: alight guiding structure, disposed on the second surface of the secondsubstrate and above the light source, and adapted to guide the firstlight beam from the light source to the second substrate.
 21. Theoptical device according to claim 10, wherein the second substrate ismade of a cover layer on a display panel of an electronic device.